Gear operated predetermined torque release wrench



April 14, 1953 H. c. PEDERSEN 2,634,640

GEAR-OPERATED, PREDETERMINED TORQUE RELEASE WRENCH Filed Nov. 30, 1949 2SHEETSSHEET 1 Aprifl M, 1953 H. c, PEDERSEN 296349540 GEAR-OPERATED,PREDETEIRMINED TORQUE RELEASE WRENCH Filed Nov. so, 1949 2 SHEETSSHEET 2ATTORNEYS a Patented Apr. 14, 1953 GEAR OPERATED PREDETERMINED TORQUERELEASE WRENCH Harry 0. Pedersen, Royal Oak, MiclL, assignor, by

direct and mesne assignments, to Clyde Engineering and ManufacturingCorporation, Royal Oak, Mich, a corporation of Michigan ApplicationNovember 30, 1949, Serial No. 130,287

2 Claims.

This invention relates to power operated Wrenches, the primary object ofthe invention being to provide means for automatically disconnecting thepower from the wrench shank when the tool has operated to tighten a nutupon a bolt to predetermined torque setting.

An important object of the invention is to provide means for moving thecoupling members to move the teeth of the coupling out of contact witheach other after the nut driven by the wrench has been tightened asrequired, thereby eliminating wear on the teeth due to the retation ofthe coupling members and teeth during overrunning of the clutch.

Another object of the-invention is to provide means for adjusting theautomatic throwout mechanism so that the throwout mechanismwill operatewhen a nut has been tightened upon a bolt to apredetermined distance ortorque setting. 1

Still another object of the invention is to provide an improvedautomatic power operated wrench which will be automatically renderedoperable by the operator in placing the wrench upon a nut disposed on abolt and applying pressure upon the wrench in the direction of the nut.

With the foregoing and other objects in view which will appear as thedescription proceeds, the

invention consists of certain novel details of construction andcombinations of parts hereinafter more fully described and pointed outin the claims, it being understood that changes may be made in theconstruction and arrangement of parts without departing invention asclaimed.

Referring to the drawings Figure 1 is a longitudinal sectional viewthrough a power wrench, constructed in accordance with the invention.

Fig. 2 is a sectional view taken on line of Fi 1.

Fig. 3 is a sectional view taken on line 33 of Fig. l.

Fig. 4 is a side elevational view of the main or body portion of thewrench.

Fig. 5 is a sectional view through the upper portion of the wrench.

Fig. 6 is a perspective view pling member of the tool.

Referring to the drawings in detail a work turning element A of thewrench comprises a main shaft 5 carrying adjacent one end a driven headB. The shaft 5 is provided intermediate its ends with a threaded portion6 with which illustrating the coufrom the spirit of the an adjustablestop collar I is threadedly engaged. The collar 1 is provided withthreaded openings 8 and wrench openings 9, whereby the collar may beadjusted longitudinally of the main shaft 5 and held by means of setscrews I0 positioned within the threaded openings 8.

This stop collar 1 provides a seat for one end of a compression coiledspring .II which encircles the shaft 5 and the opposite end of said coilspring bears against a bearing C comprising-a steel washer I2 that inturn frictionally engages the bronze washer [3 that rests against asteel washer I 4. The steel washer I4 is provided with an enlargement l5that fits within a recess it formed in the lower end of a collar I!which encircles the shaft 5 and forms a driving head D which isrotatable about and longitudinally" movable relative to the shaft orwork turning element A.

Surrounding the collar [1 and fixed thereto'as' by means of a key 22 isan outwardly extending annular ring 2| having formed in the end there ofadjacent the driven head B peripherally spaced recesses 18- ofsubstantially rectangular form.

These recesses open through the adjacent end of the ring 2| for thereception of peripherally spaced fingers 28 which are carried by adriving element 26 which is mounted for rotation on the shaft 5 adjacentthe driven head B on the side thereof remote from the driving head D;A-suitable anti-friction bearing 33 provides the-support for the drivingelement 26 on the-shaftil' Carried by the driving head D on the endthereof adjacent the driven head B is an annular row of tapered teeth 23which as illustrated in Fig. 5 are adapted to mesh with cooperatingteeth 24 on the driven head B. Said teeth 23 and being held in meshingengagement under the influence of the spring ll previously referred to.It will thus be seen that when the resistance to turning of the shaft 5attains a predetermined value, the teeth 23 will ride against theinclined surfaces of the teeth 24 to cause a separation of the drivinghead D from the driven head B against the effort of spring ll. Formed inthe ring 2| and extending radially therethrough adjacent one corner ofeach recess 18 is an arcuate recess [0 into which is fitted a roller 20.These rollers project radially outwardly beyond the periphery of thecollar I1, and secured in any suitable manner to the ring 2! inencircling relation to and overlying portions of the rollers 20 is anannular retainer 32 by means of which the rollers 20 are held in properposition in the recesses l9. As shown the rollers 20 lie in the path ofthe fingers 28 so that When turning effort is applied to the drivingelement 26, the fingers will engage the rollers and cause the drivinghead D to rotate in unison with the driving element 26.

Carried by the fingers 23 and formed at the junctions of the trailingwalls of the recesses and the ends of the fingers remote from thedriving element 26 are inclined cam surfaces 29 which, when the teeth 23and 24 approach maximum separation against the efiort of the spring Ill, engage the peripheral surfaces of the rollers 20 to exert furtherseparating effort on the parts to completely separate the teeth so thatthe driving head D may rotate without turning the work turning element Aand the points of the teeth 23 and 24 will be protected from wear. Thedriving element 26 is provided on theend thereof remote from thatcarrying the fingers 28 with clutch teeth 38 which are adapted to beengaged by the teeth 39 of a clutch member 40 which is mounted forrotation on an extension '42 of the shaft andis coupled to aconventional driven gear 48 which is operatively connected through thedrive gear 49 to the prime mover of the device. I

In use it will be seen that as the teeth 39 of the clutch 40 engage theteeth 38 of the driving element 26, assuming of course that the primemover is in operation, power will be transmitted through the fingers 28to the head D by engagement with the rollers 20. In this drivingoperation, the teeth 23 will be held in mesh with the teeth 24 under theinfluence of the spring ll so that driving effort will be transmitted tothe shaft 5. When the resistance'of the shaft 5 to turning attains apredetermined value, the inclined faces of the teeth 23 and 24 will tendto cause the driving head D to move longitudinally on the shaft 5against the efforts of the spring; -I I until the inclined cam numbers29 on the fingers-28 attain a position-which will cause them to rideonthe rollers and move the head D further against the effort of the springH until the points of teeth 23 and 24 are free from one another to thusenable the driving head D to rotate without imparting an rotary motionto the driven head B.

While in the foregoing there has been shown and described the preferredembodiment of this invention it is to be understood that minor changesin the details of construction, combination and arrangement of parts maybe resorted to without departing from the spirit and scope of theinvention as claimed.

Having thus described the invention, what is claimed is:

1. In a power driven wrench, a main shaft, a driving member havingteeth, keyed on the shaft, adriving sleeve loosely mounted on thedriving member, said driving sleeve having extensions, a collarrotatably mounted on the main shaft, said collar including an innersection having teeth meshing with the teeth of the driving member,coupling the main shaft with said collar, said collar having cut awayportions extending from one edge thereof, into which the extensionsextend, bearings mounted within the cut away portions, said extensionsengaging said bearings and rotating the collar'and main shaft as thedriving sleeve rotates, an adjustable tension spring encircling aportion of the main shaft and bearing against the collar, therebynormally urging the collar towards the driving sleeve and connecting theteeth of the collar and driving sleeve, said extensions having roundedcorners adapted to ride over the bearings, thereby disengaging the teethof the driving member and collar, said extensions resting on thebearings and holding the teeth of the driving member and collarseparated during continuous rotation of said main shaft.

2. In a torque Wrench in which driving power applied to work isautomatically discontinued when the resistance of the work to turningattains a predetermined value, said wrench comprising an elongated workturning element, a driven head fixed to said element, an annular row ofteeth having oppositely inclined faces carried by and extendinglongitudinally from one side of said driven head, a driving head mountedon said work turning element forro tation thereabout andmovementlongitudinallythereon adjacent the driven head, an annular rowof teeth having oppositely inclined facescarried by and extendinglongitudinally from the side of the driving head adjacent the drivenhead, a collar mounted on the Work turning element in spaced relation tothe driving head for adjustment longitudinally on said work turningelement, a compression coiled spring encircling the work turning elementand bearing on the collar and on the driving head for yieldingly holdingthe teeth of the driving head in mesh with those of the driven headwhereby when the resistance to turning of the work turning elementattains a predetermined value the teeth on the driving head will ride onthe teethof the driven head against the eifort of the spring and turningefiort on the work turning element will be discontinued despite thecontinued rotation of the driving head, rollers carried by and extendingradially outwardly from the driving head, fingers carried by the workturning ele ment for rotation thereabout, saidfingers-extending parallelwith said Work turning element and being adapted to engage the 'rollersfor driving the driving head, and cam surfaces on the fingers forengaging the rollers and moving the driving head against the efiort ofthe spring to completely disengage the teeth as the approachdisengagement. l

HARRY c. PEDERSENQTY References Cited in the file' of this patent UNITEDSTATES PATENTS Great Britain Oct. 24, 1934

